A South Florida hospital worker who stole more than 800 patients' Social Security numbers and sold them to a multimillion-dollar tax fraud ring, pleaded guilty to her role in the conspiracy Monday.

Betty Cole, 34, of Miami, faces a maximum of seven years in federal prison when she is sentenced later this year.

Federal prosecutors promised her they will recommend that she get a lighter punishment because she cooperated in the investigation and testified in trial against the Fort Lauderdale ringleader of the group, Alci Bonannee.

Bonannee, 36, is now serving more than 26 years in federal prison for masterminding the identity theft ring. A federal judge told Bonannee she was a "parasite and a blight on society" and prosecutors said her scheme was one of the biggest and most successful in the nation.

Bonannee's methods were so successful that she and her codefendants submitted $11.7 million worth of fraudulent income tax refunds, and the IRS approved some $4.5 million of those refunds, according to court records.

Cole, who worked as a respiratory therapist for South Miami Hospital, admitted Monday in federal court in Fort Lauderdale that she stole the names, dates of birth and Social Security numbers of more than 800 patients between June 2011 and February 2012.

Cole "prepared a handwritten list" of patients' personal identifying information that she had access to in the course of doing her job, Assistant U.S. Attorney Michael Berger told the judge in court Monday. She prepared lists on a number of occasions after Bonannee asked Cole to get the information, Cole admitted.

Cole's attorney Humberto Dominguez said his client's criminal actions were "so out of character, she's a really nice person."

"Obviously, she helped out on the bigger case [against Bonannee] and she very much regrets having had anything to do with this. She is very sorry," Dominguez said.

In a statement released shortly after the breach of patient information was discovered, Baptist Health, which operates South Miami Hospital, said that Cole had been terminated.

Several federal investigative agencies have issued reminders to patients that it may not be necessary to give a Social Security number to medical providers unless that is the only way the insurance provider can distinguish them from other clients. But medical providers may need the Social Security number to verify insurance coverage if that is how they distinguish between accounts.

Cole, who turned herself in to the U.S. Marshals Service at the courthouse early Monday, pleaded guilty to aggravated identity theft and conspiracy to possess unauthorized access devices — the patients' Social Security numbers. She was released on a $100,000 bond pending sentencing on Sept. 23.

Two other codefendants Sonyini Clay, 40, of Miami Gardens, and Chante Mozley, 34, are both serving prison terms. Clay was sentenced to more than 10 years in federal prison and Mozley is serving 3 1/2 years.

In an unrelated case, another Miami woman, Natoya Mashea Handy, 30, was sentenced Monday to four years and three months in prison for her role in another stolen identity tax refund scheme — this one involving stealing incarcerated prisoners' identities and using them to file fraudulent tax returns in 2012. A jury found Handy guilty of federal fraud and aggravated identify theft charges earlier this year.